The invention relates to a takeup machine for winding a plurality of yarns on a corresponding number of winding tubes of the type described in DE 31 36 908 A1.
In high-speed takeup machines, in particular for winding synthetic filament yarns, economic considerations have made it necessary to wind on a winding spindle a plurality of yarns, one after the other and independently of one another. From stationary yarn guides, the yarns advance each by means of a known traversing mechanism to their respective winding tube, which is mounted on the winding spindle. In this process, the leading yarn end is brought into contact with the winding spindle or winding tube by means of a yarn catching device. Such a yarn catching device is used to catch the yarn and, if need be, wind same on the starting end of the tube after forming a waste wind or a yarn reserve wind. Known are long winding spindles, which permit winding of up to eight packages at the same time. This requires an arrangement of yarn guides in spaced relationship along the winding spindle, with the spacing being greater than the actual package width. The longer the winding spindles, the more difficult it is for the operating personnel to thread the yarns on the individual winding tubes of such takeup machines. Primarily, a fast and reliable threading of the yarns is required even at very high yarn speeds.
It is also known to make for a larger number of yarns and an associated number of winding tubes the threading technique substantially independent of the skill of individual operators. In the case of this threading technique, contact yarn guides mounted on a rotatable arm extending parallel to the winding spindle, are arranged for movement along the winding spindle, and can be brought on the one hand to a threading position and on the other hand to a yarn contacting position. In the threading position, all contact yarn guides are arranged closely adjacent to one another on a part extending beyond the end of the winding spindle, so as to permit suction of a certain number of yarns with a yarn suction device, which is typically a yarn suction gun, and distribution of same in a simple manner to the contact yarn guides. In the yarn contacting position, the contact yarn guides are associated to the yarn catching devices, so that the yarns come into contact with same and can be grasped.
DE 31 36 908 A1 describes a device for the contact yarn guides, wherein each contact yarn guide is supported on a sliding element. The individual sliding elements are interconnected by a cable line mechanism, which permits moving same from the threading position to the yarn contacting position. This mechanism is relatively complicated and, thus, susceptible to breakdown. Because of the generally present extensibility of the cable in the cable line mechanism, same exhibits a conditional, limited stopping accuracy of the yarn guides that are supported by the sliding elements on the cable line mechanism.
Furthermore, DE-OS 26 27 643 and corresponding U.S. Pat. No. 4,136,834 disclose a yarn threadup device, wherein the respective contact yarn guides are attached to elements of the perforated disk type, which elements are interconnected by threaded rods. A rotation of the threaded rods permits variation of the spacings relative to one another between the elements accommodating the contact yarn guides from the yarn contacting position to the yarn threading position. This screw motion is on the one hand quite expensive, and requires a great deal of time. On the other hand, the entire mechanism must be enclosed, since it requires a corresponding lubrication for the threaded rods. Furthermore, this mechanism limits the number of yarn guides, which can be arranged respectively one after the other and side by side, as a result of limiting in the perforated disk type elements the number of tapholes that are to be accommodated for the connecting rods.
It is therefore the object of the invention to provide a takeup machine for winding a plurality of yarns to a corresponding number of packages, by which a constructionally simple threadup device is created that facilitates faster and simpler threading of the yarn by the operating personnel at high takeup speeds.